Police say dozens of gun parts found in a Saanich garbage bin have been traced back to a 2017 investigation, but they're still trying to find out why they ended up in the dumpster.

Two tent city residents found the parts wrapped in evidence bags in a dumpster near the Red Lion Inn on Douglas Street Monday night.

They brought the parts back to the Regina Park encampment and called police, according to tent city spokeswoman Chrissy Brett.

The bags appeared to be marked as evidence, and each contained multiple gun parts.

"It just said 'seized' on them and then they were all broken up into different bags all containing different pieces," said Wayne Bell, the man who found them. "It's a weird thing to find in a bin."

Police have issued a news release confirming the parts are linked to a January 2017 investigation where they were seized from a Saanich storage locker under a search warrant.

Investigators then learned the owner of the nearly 100 firearm parts had no criminal history and held a valid license to own them.

The seized parts were returned to their lawful owner, then a 20-year-old Victoria man, in February 2017.

"The items recovered last night were in the same sealed police evidence bags from when they were returned to the owner about eighteen months ago," Saanich police said. "Police are in the early stages of investigation and will contact the owner to determine how these firearm parts ended up in a dumpster."

In the release, police thanked the tent city residents who turned in the firearm parts.

Police also clarified that Canadian law does not regulate the possession of individual firearm parts like barrels, slides and trigger assemblies.